Welcome to the Community, Julio.

Let's use the verify and rebuild tools in QuickBooks Desktop (QBDT) to address the issue of why you have to manually enter the email addresses of your clients or suppliers when sending an invoice, reports, and others through email based on the screenshot you've provided. Please know that we removed the screenshot since it contains personal information. 

With the help of the verify tool that locates the common problems in a company file, the rebuild tool fixes them afterward.

Let's start by verifying your company, kindly follow the steps provided below:

1. Go to Window, then select Close All.
2. Go to File, then choose Utilities.
3. Select Verify Data. If you see:

• QuickBooks detected no problems with your data — your data is secure, so you don't need to do anything else.
• If you see an error message – you can search on our QBDT support site to learn how to fix it.
• If your data has lost integrity – if data damage is found in the file, then we have to rebuild your data.

If rebuilding the company file is needed, I'll be laying out some steps for you to follow:

1. Go to File, then select Utilities.
2. Click on Rebuild Data.
3. Follow the on-screen instructions, then press OK.
4. Select the place where you want your backup file to be saved, then tap OK.
5. Enter a new name in the File name. Click Save.

Check out this article that provides detailed guidelines on the steps I provided above: Verify and Rebuild Data in QuickBooks Desktop.

Additionally, if you plan on exporting your reports to Excel you can check this article: Export reports as Excel workbooks in QuickBooks Desktop. 

Let me know if you have other concerns with the email feature in QBDT. I’ll be here to assist you at any time. Keep safe!